why did they break up . i saw the spoilers and i havent been reading the recent chapters

Seme discovered that uke lied to get closer to him for the purpose of writing, not because he actually liked him (at first).

he a pussy he didnt let him explain?????

That appears to be what happened. Seme already was having a hard time being close to people because they would use him, so uke was supposed to be different but ultimately his goal was to use Seme as a research subject.